Implement upgrade notifications....

chrome/browser/upgrade_detector.h

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UPGRADE_DETECTOR_H_
+#define CHROME_BROWSER_UPGRADE_DETECTOR_H_
+
+#include "base/singleton.h"
+#include "base/timer.h"
+
+///////////////////////////////////////////////////////////////////////////////
+// UpgradeDetector
+//
+// This class is a singleton class that monitors when an upgrade happens in the
+// background. We basically ask Omaha what it thinks the latest version is and
+// if our version is lower we send out a notification upon:
+//   a) Detecting an upgrade and...
+//   b) When we think the user should be notified about the upgrade.
+// The latter happens much later, since we don't want to be too annoying.
+//
+class UpgradeDetector {
+ public:
+  ~UpgradeDetector();
+
+  bool notify_upgrade() { return notify_upgrade_; }
+
+ private:
+  UpgradeDetector();
+  friend struct DefaultSingletonTraits<UpgradeDetector>;
+
+  // Checks with Omaha if we have the latest version. If not, sends out a
+  // notification and starts a one shot timer to wait until notifying the
+  // user.
+  void CheckForUpgrade();
+
+  // The function that sends out a notification (after a certain time has
+  // elapsed) that lets the rest of the UI know we should start notifying the
+  // user that a new version is available.
+  void NotifyOnUpgrade();
+
+  // We periodically check to see if Chrome has been upgraded.
+  base::RepeatingTimer<UpgradeDetector> detect_upgrade_timer_;
+
+  // After we detect an upgrade we wait a set time before notifying the user.
+  base::OneShotTimer<UpgradeDetector> upgrade_notification_timer_;
+
+  // Whether we have detected an upgrade happening while we were running.
+  bool upgrade_detected_;
+
+  // Whether we have waited long enough after detecting an upgrade (to see
+  // is we should start nagging about upgrading).
+  bool notify_upgrade_;
+
+  DISALLOW_COPY_AND_ASSIGN(UpgradeDetector);
+};
+
+#endif  // CHROME_BROWSER_UPGRADE_DETECTOR_H_